Avoiding unnecessary multiple reads of I/O Device data

To avoid unnecessary reads of an I/O Device, you
can use data caching to temporarily store data read from the device
in the memory of the I/O Server. This means that if the I/O Server
receives more than one request for device data in a short time
period, instead of contacting the I/O Device a second time and
reading identical data, it can retrieve the data from the
cache.